Monitoring objects such as children, elderly, patients, visi-
tors to ensure they do not move beyond a specied range such as a room,
an area, a building or an isolation area is a common need. This monitor-
ing is usually done manually by humans. This paper introduces a solution
based on Bluetooth low energy technology combined with mobile tech-
nology to instantly detect the violation of a monitored object when he
moves beyond the allowable radius from a given point. The solution is
designed to be able to monitor thousands of objects living distributively
at undened areas with low cost, short time in deployment and with-
out violating privacy of monitored people. This solution was proposed to
support healthy center in monitoring certain COVID-19 contamination
needed to be isolated in Vietnam.